{"title":"老话题新思考:细菌孢子抗药性的秘密正在慢慢揭开","authors":"Peter Setlow, Graham Christie","doi":"10.1128/mmbr.00080-22","DOIUrl":null,"url":null,"abstract":"<p><p>The quest for bacterial survival is exemplified by spores formed by some <i>Firmicutes</i> members. They turn up everywhere one looks, and their ubiquity reflects adaptations to the stresses bacteria face. Spores are impactful in public health, food safety, and biowarfare. Heat resistance is the hallmark of spores and is countered principally by a mineralized gel-like protoplast, termed the spore core, with reduced water which minimizes macromolecular movement/denaturation/aggregation. Dry heat, however, introduces mutations into spore DNA. Spores have countermeasures to extreme conditions that are multifactorial, but the fact that spore DNA is in a crystalline-like nucleoid in the spore core, likely due to DNA saturation with small acid-soluble spore proteins (SASPs), suggests that reduced macromolecular motion is also critical in spore dry heat resistance. SASPs are also central in the radiation resistance characteristic of spores, where the contributions of four spore features-SASP; Ca<sup>2+</sup>, with pyridine-2,6-dicarboxylic acid (CaDPA); photoproduct lyase; and low water content-minimize DNA damage. Notably, the spore environment steers UV photochemistry toward a product that germinated spores can repair without significant mutagenesis. This resistance extends to chemicals and macromolecules that could damage spores. Macromolecules are excluded by the spore coat which impedes the passage of moieties of ≥10 kDa. Additionally, damaging chemicals may be degraded or neutralized by coat enzymes/proteins. However, the principal protective mechanism here is the inner membrane, a compressed structure lacking lipid fluidity and presenting a barrier to the diffusion of chemicals into the spore core; SASP saturation of DNA also protects against genotoxic chemicals. Spores are also resistant to other stresses, including high pressure and abrasion. Regardless, overarching mechanisms associated with resistance seem to revolve around reduced molecular motion, a fine balance between rigidity and flexibility, and perhaps efficient repair.</p>","PeriodicalId":18520,"journal":{"name":"Microbiology and Molecular Biology Reviews","volume":null,"pages":null},"PeriodicalIF":8.0000,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10304885/pdf/","citationCount":"0","resultStr":"{\"title\":\"New Thoughts on an Old Topic: Secrets of Bacterial Spore Resistance Slowly Being Revealed.\",\"authors\":\"Peter Setlow, Graham Christie\",\"doi\":\"10.1128/mmbr.00080-22\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The quest for bacterial survival is exemplified by spores formed by some <i>Firmicutes</i> members. They turn up everywhere one looks, and their ubiquity reflects adaptations to the stresses bacteria face. Spores are impactful in public health, food safety, and biowarfare. Heat resistance is the hallmark of spores and is countered principally by a mineralized gel-like protoplast, termed the spore core, with reduced water which minimizes macromolecular movement/denaturation/aggregation. Dry heat, however, introduces mutations into spore DNA. Spores have countermeasures to extreme conditions that are multifactorial, but the fact that spore DNA is in a crystalline-like nucleoid in the spore core, likely due to DNA saturation with small acid-soluble spore proteins (SASPs), suggests that reduced macromolecular motion is also critical in spore dry heat resistance. SASPs are also central in the radiation resistance characteristic of spores, where the contributions of four spore features-SASP; Ca<sup>2+</sup>, with pyridine-2,6-dicarboxylic acid (CaDPA); photoproduct lyase; and low water content-minimize DNA damage. Notably, the spore environment steers UV photochemistry toward a product that germinated spores can repair without significant mutagenesis. This resistance extends to chemicals and macromolecules that could damage spores. Macromolecules are excluded by the spore coat which impedes the passage of moieties of ≥10 kDa. Additionally, damaging chemicals may be degraded or neutralized by coat enzymes/proteins. However, the principal protective mechanism here is the inner membrane, a compressed structure lacking lipid fluidity and presenting a barrier to the diffusion of chemicals into the spore core; SASP saturation of DNA also protects against genotoxic chemicals. Spores are also resistant to other stresses, including high pressure and abrasion. 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引用次数: 0
摘要
一些真菌成员形成的孢子就是细菌寻求生存的例证。它们随处可见,无处不在,反映了细菌对所面临压力的适应。芽孢对公共卫生、食品安全和生物战都有影响。耐热性是孢子的标志,主要通过矿化凝胶状原生质(称为孢子核心)来抵御,孢子核心水分减少,从而最大限度地减少了大分子移动/变性/聚集。然而,干热会使孢子 DNA 发生突变。孢子在极端条件下的应对措施是多因素的,但孢子 DNA 在孢子核心中呈晶体状核状,这可能是由于 DNA 饱和了小型酸溶性孢子蛋白(SASPs),这一事实表明,减少大分子运动也是孢子耐干热的关键。SASPs 也是孢子抗辐射特性的核心,孢子的四个特征--SASP、含吡啶-2,6-二羧酸的 Ca2+、光产物裂解酶和低含水量--可将 DNA 损伤降至最低。值得注意的是,孢子环境会将紫外线光化学作用引向发芽孢子能够修复而不会产生明显诱变的产物。这种抗性延伸到可能损害孢子的化学物质和大分子。大分子会被孢子外皮阻挡,因为外皮会阻碍≥10 kDa 的分子通过。此外,具有破坏性的化学物质可能会被孢子外皮的酶/蛋白质降解或中和。不过,孢子的主要保护机制是内膜,这是一种缺乏脂质流动性的压缩结构,可阻止化学物质扩散到孢子核心;DNA 的 SASP 饱和也可抵御基因毒性化学物质。孢子还能抵抗其他压力,包括高压和磨损。无论如何,与抵抗力相关的主要机制似乎都围绕着减少分子运动、在刚性和柔性之间保持微妙平衡以及高效修复等方面。
New Thoughts on an Old Topic: Secrets of Bacterial Spore Resistance Slowly Being Revealed.
The quest for bacterial survival is exemplified by spores formed by some Firmicutes members. They turn up everywhere one looks, and their ubiquity reflects adaptations to the stresses bacteria face. Spores are impactful in public health, food safety, and biowarfare. Heat resistance is the hallmark of spores and is countered principally by a mineralized gel-like protoplast, termed the spore core, with reduced water which minimizes macromolecular movement/denaturation/aggregation. Dry heat, however, introduces mutations into spore DNA. Spores have countermeasures to extreme conditions that are multifactorial, but the fact that spore DNA is in a crystalline-like nucleoid in the spore core, likely due to DNA saturation with small acid-soluble spore proteins (SASPs), suggests that reduced macromolecular motion is also critical in spore dry heat resistance. SASPs are also central in the radiation resistance characteristic of spores, where the contributions of four spore features-SASP; Ca2+, with pyridine-2,6-dicarboxylic acid (CaDPA); photoproduct lyase; and low water content-minimize DNA damage. Notably, the spore environment steers UV photochemistry toward a product that germinated spores can repair without significant mutagenesis. This resistance extends to chemicals and macromolecules that could damage spores. Macromolecules are excluded by the spore coat which impedes the passage of moieties of ≥10 kDa. Additionally, damaging chemicals may be degraded or neutralized by coat enzymes/proteins. However, the principal protective mechanism here is the inner membrane, a compressed structure lacking lipid fluidity and presenting a barrier to the diffusion of chemicals into the spore core; SASP saturation of DNA also protects against genotoxic chemicals. Spores are also resistant to other stresses, including high pressure and abrasion. Regardless, overarching mechanisms associated with resistance seem to revolve around reduced molecular motion, a fine balance between rigidity and flexibility, and perhaps efficient repair.
期刊介绍:
Microbiology and Molecular Biology Reviews (MMBR), a journal that explores the significance and interrelationships of recent discoveries in various microbiology fields, publishes review articles that help both specialists and nonspecialists understand and apply the latest findings in their own research. MMBR covers a wide range of topics in microbiology, including microbial ecology, evolution, parasitology, biotechnology, and immunology. The journal caters to scientists with diverse interests in all areas of microbial science and encompasses viruses, bacteria, archaea, fungi, unicellular eukaryotes, and microbial parasites. MMBR primarily publishes authoritative and critical reviews that push the boundaries of knowledge, appealing to both specialists and generalists. The journal often includes descriptive figures and tables to enhance understanding. Indexed/Abstracted in various databases such as Agricola, BIOSIS Previews, CAB Abstracts, Cambridge Scientific Abstracts, Chemical Abstracts Service, Current Contents- Life Sciences, EMBASE, Food Science and Technology Abstracts, Illustrata, MEDLINE, Science Citation Index Expanded (Web of Science), Summon, and Scopus, among others.